It is often necessary in digital systems to compare the binary-encoded values of digital data words, determine which has the larger value and transmit the word having the larger or smaller value for further processing. A comparison may be performed by subtracting the two words and determining whether a positive or negative remainder is left. If a positive remainder is left, the word comprising the minuend in the subtraction operation is larger, but if a negative remainder is left the subtrahend has the larger value. Whether the minuend or the subtrahend is to be transmitted depends on whether the word with the larger or smaller value is to be further processed and the result of the subtraction operation. If a zero-valued remainder is left after the subtraction, both words have the same value and so either word could be transmitted for processing.